6. Conclusions In this paper, we demonstrated a c

6. Conclusions
In this paper, we demonstrated a customized, machine vision aided roll-to-roll ink-jet printing system
for high rate, high yield device fabrication. Based on an active alignment technique, we built up all the
necessary modules and developed the software to realize auto-registration for multi-layer stacking. The
X direction registration was realized by in-line capturing the alignment mark and determining the onset
moment of printing. The Y direction registration was achieved by real time image processing to get the
alignment mark offset, and selecting the pre-offset images to compensate for the deviation. Several
limiting factors, including the resolution of the printhead, the time required to initialize the Print Server
software, the time between the print command being sent and the Print Server being ready to start
printing, Image acquisition and processing delays, and the number of PMBs or printheads which can be
connected to a single PC, affect the overall system performance. Specifically for registration, the printer
nozzle offset, camera resolution, encoder error, print delay, image processing delay, leads to a current
registration error of about 100 μm and 200 μm for the X and the Y directions, respectively.


Acknowledgments
This work was supported by the Office of Naval Research (ONR) Small Business Technology
Transfer (STTR) contract N00014-11-C-0704 monitored by Khershed Cooper. We would also like to
acknowledge Ed Garcia from Industrial Inkjet Ltd and Kaj Larsen from KAJ’s Technical services for
their valuable suggestion in setting up the system.

Brutal honesty